The experiment methods were used to determine the absorption and transportion of L-methionine and L-phenylalanine in isolated intestine.The method simulates the physiological condition in vitro. According to the change of amino acid solutions and outside the intestine that was controlled flowing through the intestine. We detemined the L-methionine and L-phenylalanine absorbed and transported across the intestine mural directly. In the experiment, the fingerling Cyprinus carpio were employed and after 24 h starvation the intestine was obtained and cultured in vitro．The concentration levels of L-methionine and L-phenylalanine were designed at 2.5 mmol/L，5.0 mmol/L，7.5 mmol/L and 10.0 mmol/L respectively. In each solution，the penicillin was added at 0.09 mg/mL，at the same time, sulfate streptomycin was added at 0.15 mg/mL．The absorbing capacity of L-methionine and L-phenylalanine in the intestine was analyse within 21 min,the concentrations of the L-methionine and L-phenylalanine in the exudation outside the intestine mural was analysed within 60 min.The result showed that the intestine of common carp could absorb and transport effectively. The mucosal influx of both Lmethionine and Lphenylalanine occurred via a carriermediated．Active transportation entry process showed MichaelisMenten kinetics.The absorption kinetic equations of L-methionine and L-phenylalanine were 1/V=0.1251×1/［S］+0.0524（R²=0.978 1，P<0.05）and 1/V=0.1887×1/［S］+0.0288（R²=0.976 2，P<0.05）, respectively; At the same time, the kinetic constants of L-methionine and L-phenylalanine were V_max=19.08 μmol/(g·min)，K_max=2.39 mmol/L；V_max=34.72 μmol/(g·min)，K_max=6.55 mmol/L，respectively. The absorption kinetics characteristic analysis indicated that the mucosal influx and the transmural of L-methionine were higher than those of L-phenylalanine（P<0.05).